Experiments are proposed that address clinically relevant questions for the management of hearingimpaired[unreadable] patients. The information obtained will assist in deciding which approach for cochlear implantation[unreadable] is most appropriate for a particular patient. Considerable evidence is accumulating that for many patients[unreadable] the preservation of residual acoustic hearing, in addition to the stimulation provided by a cochlear implant,[unreadable] can provide important advantages compared to using only a hearing aid, or only a cochlear implant. One[unreadable] striking advantage is observed for understanding speech in background noise. In addition, this combined[unreadable] acoustic plus electric (A + E) hearing can expand the range of patients that can benefit from electrical[unreadable] stimulation, many of whom were unable to receive adequate benefit from a hearing aid. The proposed[unreadable] studies will continue our ongoing investigation of A + E hearing using the existing Hybrid (short-electrode)[unreadable] device as well as a new generation of longer, less-traumatic electrodes. The advantages and shortcomings[unreadable] of each approach will be measured in terms of preservation of hearing as well as speech understanding in[unreadable] quiet and in noise, for various patients. The goal is to develop eligibility criteria for the different device types,[unreadable] based upon the expected outcomes for various patient characteristics. Additional experiments are[unreadable] described that are designed to discover the mechanisms by which acoustic plus electric stimulation is[unreadable] integrated as an auditory sensation and what factors determine the success of the A + E approach in[unreadable] individual patients.